Elide bounds checks when kernels contains manual ones. (#486)

Author: maleadt

src/device/array.jl

@@ -48,6 +48,7 @@ Base.size(g::oneDeviceArray) = g.dims
 Base.sizeof(x::oneDeviceArray) = Base.elsize(x) * length(x)
 
 # we store the array length too; computing prod(size) is expensive
+Base.size(g::oneDeviceArray{<:Any, 1}) = (g.len,)
 Base.length(g::oneDeviceArray) = g.len
 
 Base.pointer(x::oneDeviceArray{T,<:Any,A}) where {T,A} = Base.unsafe_convert(LLVMPtr{T,A}, x)
@@ -81,7 +82,11 @@ Base.unsafe_convert(::Type{LLVMPtr{T,A}}, x::oneDeviceArray{T,<:Any,A}) where {T
 end
 
 @device_function @inline function arrayref(A::oneDeviceArray{T}, index::Integer) where {T}
-    @boundscheck checkbounds(A, index)
+    # simplified bounds check to avoid the OneTo construction, which calls `max`
+    # and breaks elimination of redundant bounds checks in the generated code.
+    #@boundscheck checkbounds(A, index)
+    @boundscheck index <= length(A) || Base.throw_boundserror(A, index)
+
     if isbitstype(T)
         arrayref_bits(A, index)
     else #if isbitsunion(T)
@@ -123,7 +128,10 @@ end
 end
 
 @device_function @inline function arrayset(A::oneDeviceArray{T}, x::T, index::Integer) where {T}
-    @boundscheck checkbounds(A, index)
+    # simplified bounds check (see `arrayref`)
+    #@boundscheck checkbounds(A, index)
+    @boundscheck index <= length(A) || Base.throw_boundserror(A, index)
+
     if isbitstype(T)
         arrayset_bits(A, x, index)
     else #if isbitsunion(T)
@@ -154,7 +162,10 @@ end
 end
 
 @device_function @inline function const_arrayref(A::oneDeviceArray{T}, index::Integer) where {T}
-    @boundscheck checkbounds(A, index)
+    # simplified bounds check (see `arrayset`)
+    #@boundscheck checkbounds(A, index)
+    @boundscheck index <= length(A) || Base.throw_boundserror(A, index)
+
     align = alignment(A)
     unsafe_cached_load(pointer(A), index, Val(align))
 end